1. Field of the Invention
The present design relates generally to the art of medical instrument systems, and more specifically to utilities for use in determining the size of objects rendered in a video frame by a medical device or instrument.
2. Description of the Related Art
Ophthalmic surgeons often record each surgical procedure performed. Recording typically involves capturing and storing medical instrument parameter settings and surgical microscope video images during the course of the procedure. Users can subsequently replay surgical procedure recordings for viewing. For example in an educational setting, user reviewing the procedure may include students, peer surgeons, and industry personnel. Today, products such as the Surgical Media Center fielded by Advanced Medical Optics provide recording functionality enabling users to create and replay, i.e. view simultaneously, video images synchronized with instrument setting parameters.
Current designs do not allow the user to easily determine the absolute size of an object as recorded in a video frame, image, or stream. Current designs are limited because the video images recorded from surgical microscope mounted cameras typically do not contain information relating the size of objects under observation, i.e. desired for viewing, during replay of the surgical procedure. In addition, current designs are further limited as they may be subjected to a wide variation in sizes of different patients' eyes and in the sizes of surgical tools employed, and differences in the surgical microscope's relative power including the amount of zoom set during the procedure. These limitations result in creating an often difficult, if not impossible, task for the user to determine the size of the object under observation during replay.
Currently, to determine the size of an object observed in a video, surgeons typically introduce an item of known size into the video image as a reference during the procedure. This known reference allows the user to assess and compare the size of objects as compared to the known reference during replay. This method is problematic for surgeons to implement because the surgeon must remember to introduce the known reference into view. Depending on the state of the surgical procedure, proper placement of the known reference may be difficult or impossible to achieve. In the situation where the surgeon successfully positions the known reference, this placement may become inconvenient and impede completing the surgical procedure. The surgeon must also keep the known reference in view of the surgical microscope to form the basis for comparison, a difficult task. Complications arise from the surgeon whose hands are typically occupied with the procedure and unable to hold the reference in place. Further, if the known reference is oriented at a different angle than the observed object, and/or if the known reference must be placed distant from the observed object, it is difficult to perform an accurate relative size measurement.
Based on the foregoing, it would be advantageous to provide a user adjustable measurement scale for use in medical instrument systems that overcomes the foregoing drawbacks present in previously known designs used in the control and operation of medical instrument systems.